Western Buddhism appears to have no real understanding of how important vijñāna (S.) viññāṇa (P.), normally rendered by ‘consciousness’ plays, both in meditation and rebirth. This consciousness is samsaric consciousness that survives death; which is the transmigrant. It re-enters womb after womb.
“It was said: ‘With consciousness as condition there is mentality-materiality.’
How that is so, Ānanda, should be understood in this way: If consciousness were not to descend into the mother’s womb, would mentality-materiality take shape in the womb?”
“Certainly not, venerable sir.” (Mahānidāna Sutta DN 15).
This same consciousness is in the intermediate state between death and the next birth which in Pali is antara and in Tibetan the all familiar bardo from The Tibetan Book of the Dead (Bardo Thodol) by Walter Evans-Wentz.
In spiritual training, meditation known as jhāna (P.) and dhyāna (S.) is the personal means for transcending samsaric consciousness; to have direct gnosis of nirvana, itself. Meditation is thus the only way to overcome and prevent consciousness from anchoring itself into another womb after death which is why meditation plays such an important role in Buddhism.
This consciousness has a number of subtle levels or states that have to be transcended and overcome before final deliverance or nirvana is attained. This is what meditation has to accomplish to realize the state of Buddhahood.
Based upon his own enlightenment, the Buddha found that this kind of meditation is the only way the continuity and flow (sota) of consciousness can be stopped. It is the state in which all conceptual and empirical experience comes to a sudden halt (P., saññā-vedayita-nirodha); which ties into the third noble truth which is the attainment of stopping (nirodha samapatti). This is what in Zen is meant by no-thought or no-mentation which, I dare say, has been overlooked these days.
What is worth noting about the state in which all conceptual and empirical experience comes to a sudden halt is that in the Pali canon this attainment or samapatti is only attainable by non-returners (anāgāmi) and Buddhas. Some regard it as the ninth meditation.
Not wishing to oversimplify Buddhist meditation but like putting many different pieces of a puzzle together meditation (jhāna/dhyāna) is about transcending samsaric consciousness which the Buddha also says is like a magician’s illusion, in addition, to also saying that “suffering is caused by consciousness” (Sutta Nipata, 734) since consciousness has managed to anchor itself, again, in conditioned existence, in a womb, for example.